On November 2, 2001, a driver on the Washington Beltway cut me off in traffic and gave someone else the finger. I remember the date because I thought, The 9/11 era is over.

In fact, the 9/11 era was both transitory and permanent. The political moment in which the United States could have done anything to address basic problems—notably, reliance on imported oil, which then cost about $25 per barrel—was gone within six months. Other consequences of 9/11 will stay with us. It is hard to imagine when airline travel will be “normal” again, or when no American troops will serve in Iraq.

For several years after the attacks, saying that a policy or idea reflected “pre-9/11 thinking” could end the discussion. But by 2005, some people, mainly academics, began arguing carefully that too much alarm over possible terrorism could be self-defeating. They said that 9/11 was a moment of unprecedented shock for America but did not overturn every previous principle of how the United States should deal with other nations or preserve its own liberties.

Early last year, a British Cabinet member announced that his government would stop using the term war on terror, because it united and perversely dignified disparate terrorist groups. The U.S. electorate made essentially the same decision this year, in rejecting Rudy Giuliani’s bid for the presidency. His approaches to economic, legal, and foreign-policy questions all began: “On 9/11 … ” Seven years afterward, that is no longer enough.

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